Garage door remote control system



Jan. 30, 1968 H. HUBER ETAL 3,356,855

GARAGE IDOORYREMOTB CONTROL SYSTEM .REMOTE 30 a2 \RECEIVER DECODER ASNOD I H. H \v\ I I mim. 60 If 1| TRANSMITTER POWER SUPPLY 65 I v 1s ig. 1.

INVENTORS. LESLIE H. HUBER and WILLIAM B. HUBER United States Patent 3,366,855 GARAGE DOOR REMOTE CONTROL SYSTEM Leslie H. Huber, 6426 Knyghton Road, Indianapolis, Ind.

46220, and William B. Huber, 233 Juniper, Park Forest, Ill. 60466 Filed Mar. 26, 1965, Ser. No. 442,964 13 Claims. (Cl. 318-16) ABSTRACT OF THE DISCLOSURE A system including a door, an electric motor to open the door, and a relay operable to energize the motor. A decoder having one signal input for a signal produced in response to a remote transmitter signal at one frequency, and another signal input for a signal produced in response to a remote transmitter signal at another frequency. A transistor circuit in said decoder and including first and second normally non-conducting transistors in series with a relay operating coil, the circuit also including a capacitor normally keeping the first transistor shut off, and a third transistor in the circuit responsive to a signal at the one signal input to turn on the first transistor and keep the second transistor turned off while a signal is present at the one signal input. A fourth transistor responsive to a signal at the other input to turn on the second transistor when there is no signal at the one input, and to turn on a fifth transistor to shut off the first transistor, whereby the relay coil is energized only after application of signals at the inputs in the proper sequence and not simultaneously, the decoder automatically returning to its initial state after removal of the input signals therefrom.

Background and description This invention relates generally to systems for opening and closing garage doors by remote wireless control, and more particularly to a system responding only to remote transmission of two different predetermined signal frequencies in sequence and within a predetermined time period.

Various types of garage door openers have been devised for responding to control signals transmitted from a remote location, whereby a person driving up to a garage door can open the door without getting out of his vehicle. Some of these devices respond to the transmission of signals at a certain frequency to cause the door to open. These devices are subject to compromise by a burglar who may also have a transmitter capable of transmitting at the required frequency.

It is therefore a general object of the present invention to provide a system which is not subject to tampering by burglars.

A further object is to provide a system requiring transmission of signals of two different frequencies in order to open a door.

A further object is to provide a system making it impossible for a burglar to open the door by employing the two required frequencies simultaneously.

Described briefly, a typicalembodiment of the present invention includes a garage door with a drive motor for opening the same, and a relay for closing the motor circuit to open the door. A remote control signal transmitter is employed which is capable of producing signal outputs at two different frequencies. A remote control signal receiver is responsive to received signals of one of the transmitter frequencies to produce a signal at one output, and it is responsive to received signals of the other transmitter frequency to produce a signal at another output. One signal output is connected to one input of a 3,366,855 Patented Jan. 30, 1968 input signals thereto for closing the motor circuit only if:

(1) a first signal of a predetermined time duration is received thereby, at the one input, and;

(2) a second signal is received at the other input within a predetermined time period subsequent to termination of the first signal.

It is only when these signals are received in sequence, that the output circuit of the decoder will be closed to activate the relay. If the second input signal is received while the first signal is still being received, the decoder will not produce the relay action.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

FIG. 1 illustrates schematically the complete garage door remote centrol system, with the door and the drive mechanism being shown on a much smaller scale than the other components, to conserve space.

FIG. 2 is a schematic diagram of the decoder and relay components of the system.

Referring now to the drawings in detail, and particularly FIG. 1 thereof, a garage door 11 is shown in the closed position, this door being of a well known type, comprising hinged sections and capable of being opened by pulling the cable 12 in the direction of the arrow 13. The cable passes over pulley 14.

To drive the cable in the direction of the arrow 13, a reversible motor 16 is employed having an output drive screw 17 on which the nut member 18 is carried and driven linearly. The nut member is connected to the cable. During forward operation of the motor it drives the screw in one rotational direction, and the cable is pulled in the direction of the arrow 13. When the motor is reversed, it drives the screw in the other direction, and the cable in allowed to return in the direction of the arrow 19. Either the weight of the door itself or suitable door return spring means, or both, can be employed to keep the cable taut when the drive motor is operated in reverse, to allow the door to close.

Power to drive the motor is supplied to input terminals 21 and 22 from a suitable power line, such as one supplying volt alternating current electrical energy, for example. One of these terminals 21 is connected to poles 23 and 24 of a manual switch 20. The other terminal 22 is connected through conductor 25 to a contactor 26 of relay 30 (FIG. 2) and to a pole 27 of the switch 20. The movable contactor 29 of the relay 30 is connected through conductor (30a, 30b) to the pole 31 of the manual switch. The illustrated switch is a double-pole, double-throw switch which normally makes contact between motor lead 34 and pole 31 and contact between motor lead 36 and pole 23. A spring 32 normally keeps the switch in this condition. It may be manually operated however by pulling the handle 33 so as to electrically connect the poles 24 and 27 with motor leads 34 and 36, respectively for reversing the motor to close the door. When the switch is in the position shown, and the contacts of relay 30 are closed, terminal 22 is connected through the relay 30 and pole 31 of switch 20 to the motor lead 34. Terminal 21 is connected to the motor lead 36 through pole 23 of the switch 20. Under these conditions the motor operates to drive the cable in the direction 13 to open the door.

A normally-closed, door-operated switch 37 (FIG. 2) may be employed between relay contactor 29 and the pole 1 31 so that, when the door is opened to a predetermined extent, the door will strike button 35 (FIG. 1) to open switch 37 and deenergize the motor.

The contacts 29 and 26 of relay 30 are closed by the decoder circuit operating relay 50 which includes the operator solenoid 38, movable contactor 39, and fixed contactor 41. Contactor 41 is connected to the positive terminal of a direct current source of electrical energy and the contactor 39 is connected to the negative terminal 43 through the operating coil 42 for the relay 30. Conventional power supply means may be employed to provide the desired potentials at terminals 40 and 43 as well as at supply inputs to the decoder and remote receiver. However terminals 40 and 43 could be connected to an alternating current source such as at terminals 21 and 22 (FIG. 1) if desired. A holding circuit is provided by the contactor 44 connected to the upper end of the coil 42. Contactor 46 of the holding circuit is connected through the normally-closed door-operated switch 47 to the terminal 40. Switch 47 like switch 37, is normally closed, but is opened when the door has opened to the extent desired so that it operates the button 35 (FIG. 1).

Referring further to FIG. 2, the output circuit of the decoder extends from power supply source 57 of positive direct current potential (B+) through resistor 56, through the emitter-collector path of transistor 54 and the emitter-collector path of transistor 53, and through the operating coil 52 of relay solenoid 38 to a source 51 of negative direct current potential (B) derived from the power supply. Both of these transi tors are normally maintained in the non-conducting state so that no current flows through the output circuit of the decoder. Therefore the contacts 39 and 41 of relay are normally open. It is only when the output circuit of the decoder is closed (i.e. conducting current) that the solenoid 38 is energized to close the contacts 39 and 41 of the relay 50.

Referring further to FIG. 2, a first control transistor 58 has the base electrode thereof connected to terminal 59 to receive an input signal from a first channel of remote control signal receiver 60 when the remote receiver is receiving signals of a first predetermined frequency from the remote control signal transmitter 65. Similarly the control transistor 61 has its base electrode connected to the terminal 62 to receive a signal input from a second channel of the remote receiver when the receiver is receiving signals of a second predetermined frequency. To operate the illustrated decoder with the PNP transistors therein as shown, the remote control signal receiver must produce negative going signals. This can readily be accomplished in any of a variety of ways well known in the art. Obviously, a decoder responsive to positive going signals would also be within the scope of this invention.

The collector of transistor 58 is connected to the source 51 of negative direct current electrical energy (B). Likewise the collector of transistor 61 is connected to source 51. A capacitor 68 is connected between the 13-- source 51 and the junction 69 between resistor 76 and resistor 67.

The emitter of transistor 58 is connected through resistor 71 to the B+ source 57. Likewise the emitter of transistor 61 is connected through resistor 73 to terminal 72. The emitter of transistor 58 is also connected through resistors 74 and 76 to the junction 69, and resistor 77 is connected between the emitter of transisor 6.1 and the base of output transistor 53. An additional transistor 78 is provided, with its base electrode connected through the resistor 79 to the emitter of transistor 61. Transistor 78 has an emitter connected to B+ source 57, and the collector thereof is connected to junction 81 between resistors 74 and 76. A conductor 82 is connected directly between the emitter of transistor 58 and the emitter of transistor 53.

Operation When no signal is present at either of the terminals 59 and 62, all of the five transistors are non-conducting. Capacitor 68 is holding a positive charge thereon derived from the B+ source through resistors 71, 74 and 76 so that the junction 69 is at a positive potential biasing transistor 54 off. When the remote control signal receiver receives signals at a first predetermined frequency, it will produce a negative going output signal at terminal 59. This signal will turn on transistor 58 and produce a negative pulse at the emitter thereof. This pulse discharges capacitor 68 through resistors 74 and 76, and during discharge of capacitor 68, the potential at junction 69 drops sufficiently to forward bias transistor 54. Transistor 54 will then remain conductive after the negative pulse is removed, because capacitor 68 must charge up again before it can again bias transistor 54 to a non-conductive state.

During the period of time that transistor 54 is conducting and capacitor 68 is recharging, if an appropriate negative signal is provided by the remote control signal receiver to the terminal 62, it will forward bias transistor 61 to produce a negative pulse at the emitter thereof. This pulse will cause output transistor 53 to conduct and will also cause transistor 78 to conduct. Transistor 53 thus completes the output circuit between terminal 51 and B+ source 57, energizing the operating coil 52 of the relay 5-3; to close the contacts 39 and 41 thereof. This energizes coil 42 and closes the relay 36 to start the door control motor 16 to open the door.

Transistor 78, when conducting, rapidly recharges capacitor 68 and this expedites the rise of potential at junction 69 to turn off transistor 54 and thus open the decoder output circuit. Of course this would normally occur before the garage door had sufliciently opened, so the holding circuit in relay 30 continues the opening of the garage door.

From the foregoing description, it can be understood that if the negative signal is not applied to input terminal 62 before capacitor 68 has recharged, the decoder output circuit will not be closed. This is because the charge on capacitor 68 will have risen to turn off transistor 54 before the signal is applied at terminal 62. This means that even though a negative signal is later applied to terminal 62, and turns on transistor 53, transistor 54 already will be turned off and the output circuit will be open, preventing activation of the relays. So it is seen that to operate the door of the present system, it is necessary to transmit the second required frequency within a predetermined time period after transmission of the first frequency. This time period is determined primarily by the time constant of the charging circuit for capacitor 68, which charging circuit includes resistors 71, 74, and 76 between junction 72 and the junction 69.

Another feature of the operation of the circuit may be best appreciated if we consider first a method by which a burglar might attempt to determine the frequencies required for operating the system. He could employ two variable frequency generators. It is conceivable that by sweeping the band of frequencies producible by these generators, the first frequency required by the remote receiver could be generated just prior to the second predetermined frequency. This would ordinarily operate the system of the present invention. To avoid this result, the emitter of transistor 58 is connected directly by conductor 82 to the emitter of transistor 53. When the first predetermined frequency causes the remote receiver to apply a negative signal to the base of transistor 58, a negative pulse is produced at the emitter thereof and applied through conductor 82 to the emitter of transistor 53. If this pulse is present when the negative signal from the other channel of the remote receiver is applied to the base of transistor 61, it will prevent the development of a forward bias across transistor 53. Therefore it is appar cut that the simultaneous application of negative signals to terminals 59 and 62 will not close the output circuit. In other words, the negative pulse at the emitter of transistor 58 must be terminated before the negative pulse at the emitter of transistor 61 can serve to activate the relay.

An unauthorized person attempting to open a door controlled by the system of the present invention, might apply a transmitted signal at the second predetermined frequency which would maintain a negative signal at the input terminal 62. Then with another signal generator he could transmit a range of frequencies until they reached the one which would cause the remote receiver to apply a negative signal to terminal 59. However the signal at terminal 59 will not be able to discharge capacitor 68 sufficiently to forward bias transistor 54, because the presence of the negative signal at the emitter of transistor 61 keeps transistor 78 conducting to maintain a potential at junction 69 which is at or near the B+ potential. Thus the presence of the negative signal at terminal 62 disables a signal at terminal 59 from forward biasing transistor 54, and the relay cannot be operated.

From the foregoing description, it will be apparent that the negative signal at terminal 59 should be a short pulse and should be received prior to the signal at terminal 62, in order to activate the relay. Also the signal at terminal 62 should be received within a short period of time after the signal at terminal 59, and this period of time is determined by the time constant of capacitor 68 and the resistor network including resistors 71, 74, 76, which are associated "therewith.

One example of components and values thereof which can be employed in the decoder, is as follows:

Description Transistor- 58 PNP 28B 56 61 PNP 28B 56 78 PNP ZSB 56 54 PNP 28B 56 53 PNP 2SB 56 Value Capacitor 68 microfarads Resistor 67 ohms 10000 71 do 1000 73 do 1000 74 do 30000 76 do 10000 77 do 10000 79 do 10000 56 do 100 Direct current potentials:

Terminal 57 volts pos 6 51 volts neg 6 59 V. DC neg 0.80 62 V. DC neg 0.80

Relay coil 52-Pull-in current minimum .01 ampere at 10V. DC. I

With respect to emitter potential.

may be employed. Examples of types which may be used are: I Manufacturer: Model description Admiral 5 D9. Andrea RCR-l;

Zenith 400Space Command.

Transmiter-receiver systems of the general types shown and described in United States Patents 2,817,025 and 2,923,918 issued Dec. 17, 1957, and Feb. 2, 1960, respectively, to Robert Adler, and 2,871,463 issued Jan. 27, 1959, to Robert W. Beckwith, may be used, if desired.

Of course it is possible within the scope of the present invention to employ transmitters and receivers capable of producing more than two different frequencies.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A door opening system comprising:

a door;

a motor connected to said door and operable, when energized, to open said door;

a wireless signal transmitter, said transmitter having a first manual actuator operable, when actuated, to transmit wireless waves at a first frequency, and said transmitter having a second manual actuator operable, when actuated, to transmit wireless waves at a second frequency;

wireless signal receiver and decoder means said decoder means having an output circuit coupled to said motor to energize said motor when said output circuit is closed;

first control circuit means coupled to said output circuit and including means receiving signals at said first frequency and responsive thereto to close a first portion and hold open a second portion of said output circuit;

and second control circuit means coupled to said output circuit and including means receiving signals at said second frequency and responsive thereto during absence of signals at said first frequency to close a second portion of said output circuit and then open said first portion thereof;

and charge storage means coupled to said first control circuit means and to said second control circuit means, said storage means being chargeable to open said first portion of said output circuit and prevent said control circuit means from closing said output circuit unless signals of said second frequency are received within a predetermined time after termination of reception of signals at said first frequency.

2. A door opening system comprising:

a door; 1

a motor connected to said door and operable, when energized, to open said door;

a supersonic signaltransmitter, said transmitter having a first manual actuator operable, when actuated, to transmit supersonic air-borne waves at a first frequency, and said transmitter having a second manual actuator operable, when actuated, to transmit supersonic air-borne Waves at a second fresupersonic signal receiver means and decoder means, said decoder means having an output circuit coupled to said motor to energize said motor when said output circuit is closed;

first control circuit means coupled to said output circuit and including means receiving signals at said first frequency and responsive thereto to close a first portion and hold open a second portion of said output circuit;

and second control circuit means coupled to said output circuit and including means receiving signals at said second frequency and responsive thereto during absence of signals at said first frequency to close a second portion of said output circuit in series 7 with said first portion to complete said output circuit and then open said first portion thereof; and charge storage means coupled to said first control circuit means and to said second control circuit means, said storage means for chargeable to open said first portion of said output circuit and prevent said first control circuit means from closing said first output circuit portion while signals of said second frequency are received. 3. In a control system, the combination comprising: mechanical drive means; switch means coupled to said drive means and to a first source of electrical energy, said switch means including an operator operable, when activated, to couple said drive means to said source; decoder means including first and second normallyopen switches coupled to said operator and a source of electrical energy, and said decoder means having first and second signal inputs; receiver means responsive to reception of wireless signals of a first character to provide a signal at said first input, and responsive to reception of wireless signals of a second character to provide a signal at said second input, said switches, when both are closed, activating said operator; and said decoder means being normally responsive to a signal at said second input to hold open said first switch during presence of said signal at said second input. 4. In a control system, the combination comprising: mechanical drive means; switch means coupled to said drive means and to a first source of electrical energy, said switch means including an operator operable, when activated, to couple said drive means to said source; decoder means including first and second normally-open switches coupled to said operator and a source of electrical energy, and said decoder means having first and second signal inputs; receiver means responsive to reception of wireless signals of a first character to provide a signal at said first input, and responsive to reception of wireless signals of a second character to provide a signal at said second input, said switches, when both are closed, activating said operator; said decoder means being normally responsive to a signal at said first input to close said first switch and hold open said second switch during presence of said signal at said first input. 5. In a control system, the combination comprising: mechanical drive means; relay means coupled to said drive means and to a first source of electrical energy, said relay means including an operator operable, when activated, to couple said drive means to said source; decoder means including first and second normally-open switches couple-d to said operator and a source of electrical energy, and said decoder means having first and second signal inputs; receiver means responsive to reception of wireless signals of a first character to provide a signal at said first input, and responsive to reception of wireless signals of a second character to provide a signal at said second input, said switches, when both are closed, activating said operator; and said decoder means being normally responsive to a signal at said second input to hold open said first switch during presence of said signal at said second input;

said decoder means being normally responsive to a signal at said first input to close said first switch and hold open said second switch during presence of said signal at said first input.

6. In a garage door control system, the combination comprising:

a supersonic signal transmitter, said transmitter having a first manual actuator operable, when actuated, to transmit supersonic air-borne waves at a first frequency, and said transmitter having a second manual actuator operable, when actuated, to transmit supersonic air-borne waves at a second frequency;

a door;

a door drive motor coupled to said door;

relay means coupling said motor to a first source of electrical energy, said relay means including an operator;

a relay control circuit coupled across a second source of electrical energy and including first and second switching transistors with their emitter-collector paths in series with said second source and with said operator;

a first charge storage capacitor connected to a base electrode of said first transistor and to a source of positive direct current charging potential, said storage capacitor being charged by said source of charging potential and normally back-biasing said first transistor so that it is non-conductive;

said source of positive charging potential being coupled to a base electrode of said second transistor and normally back-biasing said second transistor so that it is non-conductive;

a third switching transistor having its emitter coupled to said storage capacitor and its collector coupled to a source of negative direct current discharging potential;

a supersonic remote control signal receiver having first and second outputs and adapted to produce a negative signal at said first output in response to reception of a supersonic remote control signal of said first frequency, and adapted to produce a negative signal at said second output in response to reception of a remote control signal of said second frequency;

said first output being connected to the base electrode of said third transistor to forward bias and thereby render said third transistor conductive in response to reception of a remote control signal of said first frequency to connect said capacitor to said source of negative discharging potential for discharge of the positive charge on said capacitor and development of a negative charge thereon to forward bias and enable conduction by said first transistor;

a fourth switching transistor coupled to the base electrode of said second transistor and to said source of negative discharging potential, said fourth transistor having a base electrode coupled to said second output of said remote control signal receiver, said fourth transistor being thereby forward biased and rendered conductive in response to reception of a remote control signal of said second frequency to connect the base electrode of said second transistor to said source of dischanging potential to forward bias and enable conduction by said second transistor;

a fifth switching transistor coupled between said storage capacitor and said source of charging potential, said fifth transistor having 'a base electrode coupled to said source of positive charging potentail to normally back-bias and keep said fifth transistor non-conductive, the base electrode of said fifth transistor also being coupled through the emittercollector path of said fourth transistor to said source 'and , 7. In a garage door control system, the combination comprising:

a door;

a door drive motor coupled to said door;

relay means coupling said motor to a first source of electrical energy, said relay means including an operator;

a relay control circuit coupled across a second source of electrical energy and including first and second switching transistors with their emitter-collector paths in series with said second source and wit-h said operator;

a first charge storage capacitor connected to a base electrode of said first transistor and to a source of positive direct current charging potential, said storage capacitor being charged by said source of charging potential and normally back-biasing said first transistor so that it is non-conductive;

said source of positive charging potential being coupled to a base electrode of said second transistor and normally back-biasing said second transistor so that it is non-conductiveg a third switching transistor having its emitter coupled to said storage capacitor and its collector coupled to a source of negative direct current disc-barging potential;

a remote control signal receiver having first and second outputs and adapted to produce a negative signal at said first output in response to reception of a remote control signal of a first frequency, and adapted to produce a negative signal at said second output in response to reception of a remote control signal of a second frequency;

said first output being connected to the base electrode of said third transistor to forward bias and thereby render said third transistor conductive in response to reception of a remote control signal of said first frequency to connect said capacitor to said source of negative discharging potential for discharge of the positive charge on said capacitor and development of a negative charge thereon to forward bias and enable conduction by said first transistor;

a fourth switching transistor coupled to the base electrode of said second transistor and to said source of negative discharging potential, said fourth transistor having a base electrode coupled to said second output of said remote control signal receiver, said fourth transistor being thereby forward biased and rendered conductive in response to reception of a remote control signal of said second frequency to connect the base electrode of said transistor to said source of discharging potential to forward bias and enable conduction by said second transistor;

a fifth switching transistor coupled between said storage cap-acitor and said source of charging potential, said fifth transistor havinga base electrode coupled to said source of positive charging potential to normally back-bias and keep said fifth transistor nonconductive, the base electrodeof said fifth transistor also being coupled through the emittencollector path of said fourth transistor to said source of negative discharging potential when said fourth transistor is conductive, to thereupon render said fifth transistor conductive and provide a charge on said storage capacitor sufiicient to render said first transistor non-conductive;

and conductor means connecting said second transistor to said third transistor whereby conduction by said second transistor is prevented when said third transistor is conducting.

8. In a garage door control system the combination com prism g a door;

a door drive motor coupled to said door;

relay means coupling said motor to a first source of electrical energy, said relay means including an operator;

a relay control circuit coupled across a second source of electrical energy and including first and second electronic switching devices in series with said second source and with said operator;

first charge storage device connected to a control electrode of said first switching device and to a source of charging potential, said storage device being charged by said source of charging potential and holding said first switching device non-conductive;

said source of charging potential being coupled to a said first output being connected to a control electrode of said third switching device to render said third switching device conductive in response to reception of a remote control signal of said first frequency to connect said storage device to said source of discharging potential for discharge of said storage device to enable conduction by said first switching device;

a fourth electronic switching device coupled to a control electrode of said second switching device and to said source of discharging potential, said fourth switching device having a control electrode coupled to said second output of said remote control signal receiver, said fourth switching device being thereby rendered conductive in response to reception of a remote control signal of said second frequency to connect the control electrode of said second switch ing device to said source of discharging potential to enable conduction by said second switching device;

fifth electronic switching device coupled between said storage device and said source of charging potential, said fifth switching device having a control electrode coupled to said source of charging potential to normally keep said fifth switching device non-conductive, the control electrode of said fifth switching device also being coupled through said fourth switching device to said source of discharging potential when said fourth switching device is conductive, to thereupon render said fifth switching device conductive and provide a charge on said storage device sufiicient to render said first switching device non-conductive;

and conductor means connecting said second switching device to said third switching device whereby conduction by said second switching device is prevented when said third switching device is conducting.

11 9. In a garage door control system the combination comprising: a door;

a door drive motor coupled to said door;

relay means coupling said motor to a first source of electrical energy, said relay means including an operator;

a relay control circuit coupled across a second source of electrical energy and including first and second switching devices in series with said second source and with said operator;

a first charge storage device connected to a control member of said first switching device and to a source of charging potential, said storage device being charged by said source of charging potential and holding said first switching device non-conductive;

said source of charging potential being coupled to a control member of said second switching device and holding said second switching device non-conductive;

a third switching device coupled to said storage device and to a source of discharging potential;

a remote control signal receiver having first and second outputs and adapted to produce a signal at said first output in response to reception of a remote control signal of first frequency, and adapted to produce a signal at said second output in response to reception of a remote control signal of second frequency;

said first output being connected to a control member of said third switching device to render said third switching device conductive in response to reception of a remote control signal of said first frequency to connect-said storage device to said source of discharging potential for discharge of said storage device to enable conduction by said first switching device;

a fourth switching device coupled to a control member of said second switching device and to said source of discharging potential, said fourth switching device having a control member coupled to said second output of said remote control signal receiver, said fourth switching device being thereby rendered conductive in response to reception of a remote control signal of said second frequency to connect the con trol member of said second switching device to said source of discharging potential to enable conduction by said second switching device;

a fifth switching device coupled between said storage device and said source of charging potential, said fifth switching device having a control member coupled to said source of charging potential to normally keep said fifth switching device non-conductive, the control member of said fifth switching device also being coupled through said fourth switching device to said source of discharging potential. when said fourth switching device is conductive, to thereupon render said fifth switching device conductive and provide a charge on said storage device sufficient to render said first switching device non-conductive;

and conductor means connecting said second switching device to said third switching device whereby conduction by said second switching device is prevented when said third switching device is conducting.

10. In a control system, the combination comprising:

a source of electrical energy;

first and second switching devices in series with said energy source and wit-h a load device;

a first charge storage device connected to a control member of said first switching device and to a source of charging potential, said storage device being charged by said source of charging potential and holding said first switching device non-conductive;

said source of charging potential being coupled to a control member of said second switching device and holding said second switching device non-conductive;

a third switching device coupled to said storage device and to a source of discharging potential;

a remote control signal receiver having first and second outputs and adapted to produce a signal at said first output in response to reception of a remote control signal of a first frequency, and adapted to produce a signal at said second output in response to reception of a remote control signal of a second frequency;

said first output being connected to a control member of said third switching device to render said third switching device conductive in response to reception of a remote control signal of said first frequency to connect said storage device to said source of discharging potential for discharge of said storage device to enable conduction by said first switching device;

a fourth switching device coupled to a control member of said second switching device and to said source of discharging potential, said fourth switching device having a control member coupled to said second output of said remote control signal receiver, said fourth switching device being thereby rendered conductive in response to reception of a remote control signal of said second frequency to connect the control member of said second switching device to said source of discharging potential to enable conduction by said second switching device;

a fifth switching device coupled between said storage device and said source of charging potential, said fifth switching device having a control member coupled to said source of charging potential to normally keep said fifth switching device non-conductive, the control member of said fifth switching device also being coupled through said fourth switching device to said source of discharging potential when said fourth switching device is conductive, to thereupon render said fifth switching device conductive and provide a charge on said storage device sufiicient to render said first switching device nonconductive;

and conductor means connecting said second switching device to said third switching device whereby conduction by said second switching device is prevented when said third switching device is conducting.

11. In a control system the combination comprising:

a source of electrical energy;

first and second switching devices in series with said energy source and with a load device;

a first charge storage device connected to a control member of said first switching device and to a source of charging potential, said storage, device being charged by said source of charging potential and holding said first switching device non-conductive;

said source of charging potential being coupled to a control member of said second switching device and holding said second switching device non-conductive;

a third switching device coupled to said storage device and to a source of discharging potential;

a remote control signal receiver having first and second outputs and adapted to produce a signal at said first output in response to reception of a remote control signal of a first frequency, and adapted to produce a signal at said second output in response to reception of a remote control signal of a second frequency;

said first output being connected to a control member of said third switching device to render said third switching device conductive in response to reception of a remote control signal of said first frequency to connect said storage device to said source of discharging potential for discharge of said storage device to enable conduction by said first switching device;

a fourth switching device coupled to a control member of said second switching device and to said source of discharging potential, said fourth switching device having a control member coupled to said secsufiicient charge on said charge storage device to prevent said first transistor from conducting when said fourth transistor is conducting,

and a conductor connected between said third transisond output of said remote control signal receiver, said tor and said first transistor and connected through fourth switching device being thereby rendered con said third transistor directly to said energy source ductive in response to reception of a remote control when said third transistor is conducting to prevent signal of said second frequency to connect the concurrent flow into said second transistor when said trol member of said second switching device to third transistor is conductive and thus avoid closure said source of discharging potential to enable conof said relay control circuit during the presence of duction by said second switching device; the input signal at said third transistor.

and a fifth switching device coupled between said stor- 13. In a control system, the combination comprising: age device and said source of charging potential, said a relay control circuit including a source of direct curfifth switching device having a control member rent electrical energy and the series combination of coupled to said source of charging potential to nor- 15 first and second transistors and a relay operating mally keep said fifth switching device non-conduccoil and a resistor, said series combination being contive, the control member of said fifth switching device nected across said source; also being coupled through said fourth switching dea control circuit for said first transistor and including vice to said source of discharging potential when said the series combination of the emitter-collector path fourth switching device is conductive, to thereupon 0 of a third transistor, resistance means, and said enrender said fifth switching device conductive and ergy source, provide a charge on said storage device sufficient to said third transistor having a control signal input from render said first switching device non-conductive. a remote control signal receiver;

12. In a garage door control system, the combination a control circuit for said second transistor and includcomprising: 2* ing the emitter-collector path of a fourth transistor,

a relay control circuit including a source of direct curin series with said energy source, said fourth transisrent electrical energy and the series combination of tor having a control signal input from said remote first and second transistors and a relay operating control signal receiver, coil and a resistor, said series combination being cona charge storage device connected through a fifth renected across said source; sistor to one side of said source and to a point in a control circuit for said first transistor and including the control circuit for said first transistor, said first a series combination of the emitter-collector path transistor being normally non-conductive and preof a third transistor, first, second, and third resistors, venting discharge of said storage device whereby and said energy source, said storage device derives a charge from said source said third transistor having a control signal input from and applies the potential of one side thereof to said a remote control signal receiver; control circuit point to bias said first transistor nona control circuit for said second transistor and includconducting,

ing the series combination of the emitter-collector said third transistor being rendered conductive by an path of a fourth transistor, and a fourth resistor, and input signal applied to the control signal input theresaid energy source, 0 of and thereupon discharging said storage device to said fourth transistor having a control signal input said energy source and biasing said first transistor from said remote control signal receiver; into conduction,

a charge storage device connected through a fifth resaid fourth transistor being rendered conductive by an sistor to one side of said source and to a point in the input signal applied to the control signal input therecontrol circuit for said first transistor, said first tranof to thereupon bias said second transistor into consistor being normally non-conductive and preventing duction, discharge of said storage device whereby said stora fifth transistor connected between said energy source age device derives a charge from said energy source and said second transistor, said fifth transistor havand applies the potential at the one side of said ing a control signal input connected through a sixth energy Source to Said Control Circuit Point t bias resistance to said one side of said source to normally said first transistor non-conducting, bias said fifth transistor non-conducting, the control said third transistor being rendered conductive by an signal input of said fifth transistor being connected input Signal pp to the control Signal input thereto said fourth transistor whereby said fifth transistor of and thereupon discharging said storage device to is forward biased when said fourth transistor is said energy source and biasing said first transistor rendered conductive, into conduction, said fifth transistor, when conductive, maintaining a said fourth transistor being rendered conductive by an sufficient charge on said charge storage device to input signal applied to the control signal input thereprevent said first transistor from conducting when of to thereupon bias said second transistor into consaid fourth transistor is conducting. duction,

a fifth transistor connected between said energy source References Cited and said second transistor, said fifth transistor having UNITED STATES PATENTS a control signal input connected through a sixth re- 2,543,789 3/1951 MacMiHan 318*16 sistance to said one side of said source to normally 2 558 888 7/1951 T M 318 16 X bias said fifth transistor non-conducting, the control nm e signal input of said fifth transistor being connected 2600405 6/1952 Hoeppner 340.471 3,022,493 2/1962 Tschumi et al. 340-171 to said fourth transistor whereby said fifth transistor is forward biased when said fourth transistor is rendered conductive,

said fifth transistor, when conductive, maintaining a ORIS L. RADER, Primary Examiner.

B. A. COOPER, Assistant Examiner. 

